Polyurethane with delayed relaxation behaviour for compression products

ABSTRACT

The invention relates to medical aids, in particular compression products, such as compression stockings or bandages. More specifically, the invention relates to compression products comprising fibre forming polyurethane polymers showing a delayed continuous relaxation behaviour. The invention furthermore relates to polyurethane polymers containing N-diol and corresponding quaternised polyurethane polymers, to a process of producing the polyurethane polymers, to blends with elastane, as well as to uses.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Stage Application of InternationalApplication Number PCT/EP2018/071535, filed Aug. 8, 2018; which claimspriority to European Patent Application Number 17185611.5, filed Aug. 9,2017.

The invention relates to medical aids, in particular compressionproducts, such as compression stockings or bandages. More specifically,the invention relates to compression products comprising fibre formingpolyurethane polymers showing a delayed continuous relaxation behaviour.The invention furthermore relates to polyurethane polymers containingN-diol and corresponding quaternised polyurethane polymers, to a processof producing the polyurethane polymers, to blends with elastane, as wellas to uses.

STATE OF THE ART

Compression stockings are a specialised hosiery designed to help preventthe occurrence of, and to guard against further progression of, venousdisorders, such as oedema, phlebitis and thrombosis. Such stockings areelastic garments worn around the leg, thereby compressing the limb. Thisreduces the diameter of distended veins and increases venous blood flowvelocity and valve effectiveness.

In the clinical or ambulatory setting, the applying of compressionstockings usually is performed by a physician or nurse. Alternatively,compression stockings are applied by patients themselves, for example athome, also on a daily basis.

Fit is critical to the therapeutic effect of compression stockings.Therefore, the proper sized stocking is first determined by measuringthe legs. The correct application of compression stockings may also becritical, which is why medical personnel or the patient needs to betrained carefully.

Due to the compression intended to be provided to the leg, the materialcompression stockings are made of must not be too elastic andexpansible, and thus compression stockings can be hard to put on. Thisis particularly true in cases where the patient is weak, bedridden orinvalid, or has to experience pain.

Thus, the development of compression stockings and other medicalcompression products that ensure good compression, while at the sametime are comfortable to apply, is still challenging.

Usually, elastic polymers incorporated in the compression products arethe target of efforts of improvement. One popular polymer often usedwhen elasticity is desired is elastane.

Elastane (spandex, Lycra®) is a polyether-polyurea block copolymercontaining at least 85% polyurethane. It was invented in 1958 atDuPont's and introduced onto the market in 1962. Synthetic fibres ofelastane are known for their exceptional elasticity: After beingstrongly expanded, an elastane fibre virtually recovers its originallength. Insofar, elastane is an elastomer like natural rubber, but isstronger and more durable. Apart from medical compression products,elastane is widely used in textile and clothing industry, e.g. intights, corsetry articles or sportswear.

US 2008/0249454 discloses compression stockings constructed from a knitfabric comprising a taut elastic material providing sufficient stretchto allow the stockings to be easily placed on a foot. Spandex is amaterial considered to be incorporated in the stockings.

WO 2011/132011 discloses a knitted-type compression item with atherapeutic and/or physiological effect, designed for facilitating thepulling-on thereof, with a high level of compression of more than 20mmHg, comprising a double-helix plated weft yarn with an elastomer core,especially elastane, over the entirety of the item produced.

Several other elastic polymers are also used in compression products,polyurethane being one of them. Polyurethane (PU) is a polymer made of amultitude of molecular units, which are joined by urethane (carbamate)groups. Basically, the polymer is produced through step polymerisation(polyaddition), in which process a monomer containing at least twoisocyanate functional groups (—N═C═O) reacts with another monomercontaining at least two hydroxyl (alcohol) (—OH) groups, thereby formingthe urethane group (—NH—CO—O—).

US 2007/0113593 discloses functional compression socks comprisingpolyurethane.

US 2010/0191163 discloses a dynamic-response anatomical bandaging systemcomprising a polyurethane foam layer.

An interesting approach in the improvement of compression products isthe usage of shape memory polymers. Shape memory materials are featuredby the ability to recover their original shape from a significant andseemingly plastic deformation when a particular stimulus is applied(shape memory effect). After deformation by stretching, fibres of shapememory polymers can be triggered for shape recovery by various stimuli,such as light (UV and infrared light), chemical stimuli (moisture,solvent, pH change), heat (e.g., in thermo-responsive shape memorypolymers), an electric or magnetic field, or radiation. The idea behindthe usage of shape memory polymers is that the compression product canbe applied in a temporarily preserved expanded shape. Upon theappropriate stimulus, the compression product eventually relaxes, i.e.reverses the deformation, thereby building up a compression.

WO 2012/045427 discloses medical aids, in particular body supportbandages and orthotics, for the human or animal body, comprising atleast one element which generates or delivers a supporting force,compression or introduction of pressure, and which comprises shapememory material or consists thereof. Polyurethane is contemplated as theshape memory material. The shape memory effect is triggered by bodytemperature.

WO 2013/149985 discloses a knitted fabric containing a shape memorymaterial and a swelling agent. Polyurethane is considered to serve asthe shape memory material.

CN 105078652 discloses an intelligent compression system based on shapememory material.

In any case, high standards are to be demanded of elastic polymers foruse in medical compression products. They shall provide good compressionand, at the same time, involve good application properties.Additionally, they should show excellent tensile strength, compatibilitywith medical applications, skin-friendliness, suitability for daily use,and good washing properties.

There is still a need for improvement of elastic polymers intended foruse in medical compression products.

It is therefore an object of the invention to provide improved elasticpolymers and thus improved medical compression products.

SUMMARY OF THE INVENTION

The invention achieves the object as defined in the independent claimsand as described below under different aspects. Specific embodiments aredefined in dependent claims and also described below.

In a first aspect, the invention provides a compression productcomprising or consisting of an elastic component or material,

the elastic component or material being capable of applying acompression or a supporting force or a local pressure to a part of thebody of a subject,

the elastic component or material furthermore being capable of passingthrough a first phase during which the component or material isexpanded, a second phase during which the component or material relaxeswithout recovering or completely recovering its original shape, or onlypartially recovering its original shape, and a third phase during whichthe component or material recovers its original shape, or virtuallyrecovers or nearly completely recovers its original shape, preferablysuccessively recovers its original shape, more preferably recovers itsoriginal shape with successive deceleration,

wherein relaxation, preferably the second phase, more preferably thesecond and third phases, is/are self-initiated, preferably is/areinitiated autonomously or spontaneously in the absence of an externalstimulus.

In one embodiment of the compression product, the elastic component ormaterial comprises or consists of:

-   -   (a) a non-quaternised polyurethane (PU) polymer containing        N-diol (PU-N); and/or    -   (b) a quaternised polyurethane (PU) polymer or ionomer        containing quaternised N-diol (PU-N+);        -   and, optionally,    -   (c) elastane.

In a second aspect, the invention provides a compression productcomprising or consisting of an elastic component or material comprisingor consisting of:

-   -   (a) a non-quaternised polyurethane (PU) polymer containing        N-diol (PU-N); and/or    -   (b) a quaternised polyurethane (PU) polymer or ionomer        containing quaternised N-diol (PU-N+);        -   and, optionally,    -   (c) elastane.

In one embodiment of the first or second aspect, the compression productis a medical compression product.

In one embodiment of the first or second aspect, the compression productis selected from the group consisting of a compression hosiery,preferably a compression stocking, sock, knee sock, tights, panty hose,or maternity panty hose, a compression knee guard, a compression armsleeve, a compression waist attachment, belt or girdle, a compressionbandage, a body-supporting bandage, an orthosis, a prosthesis liner, acompression wound dressing, a compression plaster or patch, and acompression garment, preferably a compression garment for medicalpurposes.

In one embodiment of the second aspect, the compression product, or theelastic component or material is capable of applying a compression or asupporting force or a local pressure to a part of the body of a subject.

In one embodiment of the first or second aspect, the part of the body isselected from the group consisting of a limb, a leg, a thigh, a lowerleg, a knee, an arm, an upper arm, a forearm, an elbow, a hand, afinger, a wrist, a foot, a heel, a toe, an ankle, an Achilles tendon, ashoulder, the upper body, the lower body, the waist, the neck, a part ofthe head, a cheekbone, the forehead, the nose, and the chin of asubject.

In one embodiment of the first or second aspect, the subject is a human,preferably a human patient or an athlete. In an alternative embodiment,the subject is an animal, preferably a companion animal or a sportanimal.

In one embodiment of the first or second aspect, the subject is the userof the medical compression product, e.g. a patient, who applies andwears the compression product. In another embodiment, a patient wearsthe medical compression product, which on the other hand is applied by athird person, e.g. a nurse.

In one embodiment of the first or second aspect, the compression productcomprises at least one portion, or two or more portions, comprising orconsisting of the elastic component or material, and at least onedifferent portion, or two or more different portions, not containing theelastic component or material.

In one embodiment of the first or second aspect, the portion comprisingor consisting of the elastic component or material is located in an areasupposed to come in contact with a part of the body of a subject, whichpart is intended to be subjected to compression. Preferably, the part ofthe body is selected from the group consisting of a knee, a patella, acalf, an elbow, a wrist, a heel, a toe, an ankle, and an Achillestendon. Optionally, the area is the ankle area or the calf area of acompression stocking, the patella area of a compression knee guard, theelbow area of a compression sleeve, or the wound area of compressionwound dressing.

In one embodiment of the first or second aspect, the compression productcomprises two, three or more portions which differ in the elasticcomponent or material. Optionally, an elastic component or material in aportion located in the calf area of a compression stocking is capable ofproviding a stronger compression as compared to an elastic component ormaterial in a portion located outside the calf area. Suchcompartmentation of a compression stocking may allow activation of thecalf musco-venous pump.

In one embodiment of the first or second aspect, the compression productcomprises or consists of an elastic component or material according tothe invention (cf. fifth aspect).

In one embodiment of the first or second aspect, the compression productcomprises or consists of elastic fibres, filaments, threads, or yarnsaccording to the invention (cf sixth aspect).

In one embodiment of the first or second aspect, every fibre, filament,thread, or yarn in the medical compression product comprises or consistsof an elastic component or material according to the invention.

In one embodiment of the first or second aspect, the amount of elasticfibres, filaments, threads, or yarns according to the invention in themedical compression product is about 1 to 100%, about 5 to 95%, about 10to 90%, about 20 to 80%, about 30 to 50%, about 40 to 60%, or about 55to 70%, related to the total amount of fibres, filaments, threads, oryarns.

In one embodiment of the first or second aspect, the compression productcomprises or consists of a compressive base fabric according to theinvention (cf. seventh aspect).

In one embodiment of the first or second aspect, the compression productcomprises or consists of a polyurethane (PU) polymer containing N-diolaccording to the invention (cf. eighth or ninth aspect).

In a third aspect, the invention provides uses of a compression productaccording to the invention (cf. first or second aspect) in the fields ofphlebology, orthopaedics, foot care, surgery, post-surgery care, traumamanagement, wound care, or sports.

In a fourth aspect, the invention provides uses of a compression productaccording to the invention (cf first or second aspect) for treatment orprevention or management of impaired musco-venous pump performance,compromised venous circulation, venous insufficiency, preferably chronicvenous insufficiency, oedema, phlebitis, thrombosis, preferably deepvein thrombosis, venous embolism, lymphoedema, ulcer, preferably ulcerof the lower leg, aching legs, varicose veins, spider veins, or the“economy class syndrome” (ECS).

In a fifth aspect, the invention provides an elastic component ormaterial comprising or consisting of:

-   -   (a) a non-quaternised polyurethane (PU) polymer containing        N-diol (PU-N); and/or    -   (b) a quaternised polyurethane (PU) polymer or ionomer        containing quaternised N-diol (PU-N+);        -   and, optionally,    -   (c) elastane.

In one embodiment, the elastic component or material comprises orconsists of a blend of the non-quaternised PU polymer and/or thequaternised PU polymer or ionomer and elastane.

In one embodiment, the elastic component or material comprises orconsists of a blend of the non-quaternised PU polymer and elastane. Thisembodiment is preferred.

In one embodiment, the elastic component or material comprises orconsists of two or more different non-quaternised PU polymers and/orquaternised PU polymers or ionomers.

In one embodiment, the elastic component or material comprises orconsists of fibres, filaments, threads, or yarns according to theinvention (cf. sixth aspect). In one embodiment, such fibre, filament,thread, or yarn is treated with a powder or oil, such as SiO₂ powder,silicone oil or linseed oil, to prevent sticking of the fibre, filamentetc., especially when it is wound up.

In one embodiment, the elastic component or material has been processedto a thread or yarn, preferably according to the invention.

In one embodiment, the elastic component or material has been processedto a textile or fabric, preferably a compressive base fabric, preferablyaccording to the invention.

In one embodiment, the elastic component or material comprises orconsists of a polyurethane (PU) polymer containing N-diol according tothe invention (cf. eighth or ninth aspect).

In one embodiment, the elastic component or material is capable ofpassing through a first phase during which the component or material isexpanded, a second phase during which the component or material relaxeswithout recovering or completely recovering its original shape, or onlypartially recovering its original shape, and a third phase during whichthe component or material recovers its original shape, or virtuallyrecovers or nearly completely recovers its original shape, preferablysuccessively recovers its original shape, more preferably recovers itsoriginal shape with successive deceleration.

In one embodiment, the elastic component or material recovers partiallyduring the second phase by about 15 to 80%, more preferably by about 20to 75%, optionally by about 15 to 30% or 20 to 25%, optionally by about65 to 80 or 70 to 75% of the total length to which the elastic componentor material had been expanded during the first phase.

In one embodiment, the elastic component or material recovers partiallyduring the second phase by about 15 to 55%, preferably by about 20 to50%, more preferably by about 25 to 45%, optionally by about 15 to 30%or 20 to 25%, optionally by about 40 to 55 or 45 to 50% of the totallength to which the elastic component or material had been expandedduring the first phase.

In one embodiment of the elastic component or material, relaxation,preferably the second phase, more preferably the second and third phasesis/are self-initiated, preferably is/are initiated autonomously orspontaneously in the absence of an external stimulus.

In one embodiment, the elastic material or component has a delayedrelaxation behaviour, preferably a delayed continuous relaxationbehaviour.

In a sixth aspect, the invention provides an elastic fibre, filament,thread, or yarn comprising or consisting of an elastic component ormaterial according to the invention (cf fifth aspect).

In one embodiment, the elastic fibre, filament, thread, or yarncomprises or consists of a polyurethane (PU) polymer containing N-diolaccording to the invention (cf eighth or ninth aspect).

In one embodiment, the elastic fibre, filament, thread, or yarn consistsof the elastic component or material, or the PU polymer (e.g. in termsof a “naked” thread or yarn).

In one embodiment, the elastic thread or yarn comprises or consists of acore portion and/or a cover portion (e.g. a coating) comprising orconsisting of the elastic component or material, or the PU polymer.

In one embodiment, the elastic thread or yarn comprises or consists of acore thread or yarn, and a cover thread or yarn wound around the corethread and yarn, respectively, the core thread or yarn and/or the woundcore thread or yarn comprising or consisting of the elastic component ormaterial, or the PU polymer.

In one embodiment, the elastic fibre, filament, thread, or yarn has beenprocessed to a textile or fabric, preferably a compressive base fabric,more preferably according to the invention.

In one embodiment of the elastic fibre, filament, thread, or yarn, thetextile or fabric is a knitted fabric, an interlaced fabric, a wovenfabric, or a felt.

In a seventh aspect, the invention provides a compressive base fabric,preferably a compressive base knitted fabric, comprising or consistingof an elastic component or material according to the invention (cf fifthaspect).

In one embodiment, the compressive base fabric comprises or consists ofa polyurethane (PU) polymer containing N-diol according to the invention(cf eighth or ninth aspect).

In one embodiment, the compressive base fabric comprises or consists ofa base thread and a weft thread, the latter being drawn through,inserted over-and-under, the length of the base thread.

In one embodiment of the compressive base fabric, the base thread and/orthe weft thread, and optionally at least one additional thread, e.g. afiller thread, comprises or consists of the elastic component ormaterial, or the PU polymer.

In one embodiment, the compressive base fabric is a flat knitted fabricor a circular knitted fabric.

In an eighth aspect, the invention provides a polyurethane (PU) polymerhaving a delayed continuous relaxation behaviour, wherein relaxation isself-initiated, preferably is initiated autonomously or spontaneously inthe absence of an external stimulus.

In one embodiment, the PU polymer additionally has features orcombinations thereof as defined in the ninth aspect.

In a ninth aspect, the invention provides a polyurethane (PU) polymercontaining N-diol.

In one embodiment, the PU polymer comprises at least one N-diol monomercomponent, preferably two or more, more preferably several or amultitude of N-diol monomer components.

In one embodiment, the PU polymer is a non-quaternised PU polymer(PU-N). This is a preferred embodiment.

In one embodiment, the PU polymer is a quaternised PU polymer (PU-N+).

In one embodiment, the PU polymer is a quaternised PU ionomer (PU-N+).

In one embodiment, the quaternised PU polymer or ionomer is derived froma non-quaternised PU polymer.

In one embodiment, the PU polymer is capable of being actively expandedand of relaxation upon release.

In one embodiment, the PU polymer is capable of passing through arelaxation process comprising or consisting of an immediate relaxationphase and a subsequent successive compression phase.

In one embodiment, the PU polymer is capable of passing through a firstphase during which the material is expanded, a second phase during whichthe material relaxes without recovering or without completely recoveringits original shape or with only partially recovering its original shape,and a third phase during which the PU polymer recovers its originalshape, or virtually recovers or nearly completely recovers its originalshape, preferably successively recovers its original shape, morepreferably recovers its original shape with successive deceleration.

In one embodiment, the PU polymer recovers partially during the secondphase by about 15 to 80%, more preferably by about 20 to 75%, optionallyby about 15 to 30% or 20 to 25%, optionally by about 65 to 80 or 70 to75% of the total length to which the PU polymer had been expanded duringthe first phase.

In one embodiment, the PU polymer recovers partially during the secondphase by about 15 to 55%, preferably by about 20 to 50%, more preferablyby about 25 to 45%, optionally by about 15 to 30% or 20 to 25%,optionally by about 40 to 55 or 45 to 50% of the total length to whichthe PU polymer had been expanded during the first phase.

In one embodiment of the PU polymer, relaxation, preferably the secondphase, more preferably the second and third phases is/areself-initiated, preferably is/are initiated autonomously orspontaneously in the absence of an external stimulus.

In one embodiment of the PU polymer, relaxation is self-initiated orinitiated without the impact of an external stimulus.

In one embodiment of the PU polymer, relaxation is self-initiatedimmediately upon release.

In one embodiment of the PU polymer, relaxation is self-initiated atroom temperature.

In one embodiment, the PU polymer shows a delayed relaxation behaviour,preferably a delayed continuous relaxation behaviour, more preferably arelaxation behaviour which is delayed as compared to that of a PUpolymer not containing N-diol.

In one embodiment of the PU polymer, the delayed relaxation behaviour isdelayed in respect of duration of the immediate relaxation phase and/orsuccessive compression phase.

In one embodiment of the PU polymer, the delayed relaxation behaviour isdelayed in respect of the relative amount of relaxation achieved duringthe immediate relaxation phase and/or successive compression phase.

In one embodiment of the PU polymer, the delayed relaxation behaviour isdelayed in respect of duration of the whole relaxation process.

In one embodiment of the PU polymer, the delayed relaxation behaviour isnot delayed in respect of the initiation of relaxation.

In one embodiment, the PU polymer does not show a shape memory to theeffect that shape recovery is initiated through the impact of anexternal stimulus.

In one embodiment, the quaternised PU polymer or ionomer comprises atleast one ionic group, preferably two or more, more preferably severalor a multitude of ionic groups.

In one embodiment, the quaternised PU polymer or ionomer comprises up toabout 15%, preferably between about 1, 2, or 3 and 10%, more preferablybetween about 4 and 10%, even more preferably between about 3 and 7%, orbetween about 7 and 11%, even more preferably between about 4 and 6%, orbetween about 8 and 10%, most preferably about 5%, or about 9% of ionicgroups, related to the total moles of the PU polymer.

In one embodiment of the quaternised PU polymer or ionomer, the ionicgroup is a quaternised N-containing group or a quaternary amino group,preferably a quaternised amino alkyl group. Optionally, the quaternisedamino alkyl group is the only type of ionic group.

In one embodiment of the quaternised PU polymer or ionomer, thequaternised amino alkyl group contains alkyl groups of differentlengths. Preferably, the quaternised amino alkyl group contains alkylgroups selected from the group consisting of methyl, ethyl, propyl,butyl, pentyl, hexyl, heptyl, and octyl groups. More preferably, thequaternised amino alkyl group contains a butyl group. Most preferably,the quaternised amino alkyl group contains one butyl group and twomethyl groups (—N⁺—(CH₃)₂(CH₂—CH₂—CH₂—CH₃).

In one embodiment of the quaternized PU polymer or ionomer, thequaternised amino alkyl group is part of the N-diol monomer component.

In one embodiment, the PU polymer comprises or consists of at least onemolecular unit, preferably two or more molecular units, more preferablyseveral or a multitude of molecular units, consisting of a diol monomercomponent and an isocyanate monomer component.

In one embodiment of the PU polymer, the diol monomer component and theisocyanate monomer component are joined by a urethane link.

In one embodiment of the PU polymer, a diol monomer (which the diolmonomer component is derived from) is selected from the group consistingof a N-diol, a 1,4-butanediol (BD) and a poly(tetrahydrofuran) (P(THF)).

In one embodiment, the PU polymer comprises or consists of a firstmolecular unit consisting of a N-diol monomer component and anisocyanate monomer component, a second molecular unit consisting of a1,4-butanediol monomer component and an isocyanate monomer component,and a third molecular unit consisting of a P(THF) monomer component andan isocyanate component.

In one embodiment of the PU polymer, the first, second and thirdmolecular units are joined by a urethane link, respectively.

In one embodiment of the PU polymer, the isocyanate monomer component inthe third, second and third molecular units is identical or different.Preferably, the isocyanate monomer component is the same.

In one embodiment of the PU polymer, an isocyanate monomer (which theisocyanate monomer component is derived from) ismethylenedi(phenylisocyanate) (MDI).

In one embodiment of the PU polymer, the N-diol isbis(2-hydroxyethyl)-3,3′-((2-(dimethylamino)ethyl)azanediyl)-dipropionateorN′,N′-bis(3-(2-hydroxyethoxy)-3-oxopropyl)-N,N-dimethylethylendiamine.

In one embodiment of the PU polymer, a quaternised N-diol monomercomponent is produced by quaternization of a quaternisable N-diolmonomer component.

In one embodiment of the PU polymer, a quaternisable N-diol monomer(which the quaternisable N-diol monomer component is derived from) isproduced from 2-dimethylaminoethylamine (DMAE) and2-hydroxyethylacrylate (HEA), preferably in a ratio of 1:2 (DMAE:HEA),more preferably in the presence of tetrahydrofuran (THF) at 45° C. for24 hours.

In one embodiment of the PU polymer, the relative amounts of N-diol,P(THF) and BD monomer components are about 50:25:25%.

In one embodiment, the quaternised PU polymer or ionomer comprises anamount of quaternised N-containing groups of up to about 15%, preferablybetween about 1, 2, or 3 and 10%, more preferably between about 4 and10%, even more preferably between about 3 and 7%, or between about 7 and11%, even more preferably between about 4 and 6%, or between about 8 and10%, most preferably about 5%, or about 9% of ionic groups, related tothe total moles of the PU polymer.

In one embodiment, the PU polymer, preferably the non-quaternised PUpolymer, has a glass transition temperature T_(g) of between about 20and 60° C., preferably of between about 30 and 50° C., more preferablyof between about 35 and 45° C., most preferably of about 40° C.

In one embodiment, the PU polymer, preferably the quaternised PUpolymer, more preferably being quaternised at about 29%, has a glasstransition temperature T_(g) of about 40° C. and/or 70° C.

In one embodiment, said glass transition temperature is measured bydynamic-mechanical thermo-analysis (DMTA).

In one embodiment, the PU polymer, preferably the non-quaternised PUpolymer, has a degradation temperature of between about 150 and 200° C.,preferably between about 170 and 195° C., more preferably between about180 and 190° C., most preferably of about 185° C.

In one embodiment, the PU polymer, preferably the non-quaternised PUpolymer, has as fracture strain of between about 1,300 and 1,450 dL [%],more preferably between about 1,350 and 1,400 dL [%], more preferablybetween about 1,380 and 1,395 dL [%], most preferably of about 1,388 dL[%].

In one embodiment, the non-quaternised PU polymer is blended with atleast one, two or more, or several quaternised PU polymers or ionomers.

In one embodiment, the quaternised PU polymer or ionomer is blended withat least one, two or more, or several non-quaternised PU polymers.

In one embodiment, the non-quaternised PU polymer and/or quaternised PUpolymer or ionomer is blended with an elastane.

In one embodiment, the PU polymer is fibre or filament forming,preferably is fibre forming.

In one embodiment, the PU polymer forms or has been processed to athread or yarn.

In one embodiment, the PU polymer has been processed to a textile orfabric, preferably a compressive fabric, optionally a compressive basefabric.

In a tenth aspect, the invention provides a blend comprising orconsisting of:

-   -   (a) a non-quaternised polyurethane (PU) polymer containing        N-diol (PU-N); and/or    -   (b) a quaternised polyurethane (PU) polymer or ionomer        containing quaternised N-diol (PU-N+);        -   and    -   (c) elastane.

In one embodiment, the blend comprises or consists of between about 5and 40% (by weight) non-quaternised PU polymer or quaternised PU polymeror ionomer, and between about 60 and 95% (by weight) elastane.

In one embodiment, the blend comprises or consists of between about 10and 30% (by weight) non-quaternised PU polymer or quaternised PU polymeror ionomer, and between about 70 and 90% (by weight) elastane.

In one embodiment, the blend consists of about 30% (by weight)non-quaternised PU polymer or quaternised PU polymer or ionomer, and 70%(by weight) elastane.

In one embodiment, and in a preferred embodiment, the blend consists ofabout 10% (by weight) non-quaternised PU polymer or quaternised PUpolymer or ionomer, and 90% (by weight) elastane. The advantage of thisembodiment is that the major amount of elastic polymer in the blend iscommercially available and comparatively inexpensive elastane.

In one embodiment, an in a preferred embodiment, the blend comprises orconsists of a non-quaternised PU polymer and elastane. The advantage ofthis embodiment is that the process step of quaternisation can beavoided.

In one embodiment, the blend comprises or consists of at least one, twoor more, or several non-quaternised PU polymers and elastane.

In one embodiment, the blend is fibre or filament forming, preferably isfibre forming.

In one embodiment, the blend forms or has been processed to a thread oryarn.

In one embodiment, the blend has been processed to a textile or fabric,preferably a compressive fabric, optionally a compressive base fabric.

In one embodiment of the blend, the non-quaternised PU polymer and/orthe quaterised PU ionomer is one according to the invention (cf. eighthor ninth aspect).

In one embodiment, the blend is capable of passing through a first phaseduring which the blend material is expanded, a second phase during whichthe blend material relaxes without recovering or without completelyrecovering its original shape or with only partially recovering itsoriginal shape, and a third phase during which the blend materialrecovers its original shape, or virtually recovers or nearly completelyrecovers its original shape, preferably successively recovers itsoriginal shape, more preferably recovers its original shape withsuccessive deceleration.

In one embodiment, the blend recovers partially during the second phaseby about 15 to 80%, more preferably by about 20 to 75%, optionally byabout 15 to 30% or 20 to 25%, optionally by about 65 to 80 or 70 to 75%of the total length to which the blend material had been expanded duringthe first phase.

In one embodiment, the blend recovers partially during the second phaseby about 40 to 80%, preferably by about 50 to 75%, optionally by about50 to 60% or 60 to 75% of the total length to which the blend materialhad been expanded during the first phase.

In one embodiment of the blend, relaxation, preferably the second phase,more preferably the second and third phases is/are self-initiated,preferably is/are initiated autonomously or spontaneously in the absenceof an external stimulus.

In an eleventh aspect, the invention provides uses of an elasticcomponent or material (cf. fifth aspect), an elastic fibre, filament,thread, or yarn (cf. sixth aspect), a compressive base fabric (cf.seventh aspect), a polyurethane (PU) polymer containing N-diol (cf.eighth or ninth aspect), or a blend (cf. tenth aspect) according to theinvention in a compression product, preferably a medical compressionproduct, or in a process for producing such a product.

In a twelfth aspect, the invention provides uses of a polyurethane (PU)polymer containing N-diol according to the invention (cf. eighth orninth aspect) in a process for producing a compression product, anelastic component or material, an elastic fibre, filament, thread, oryarn, or a compressive base fabric, preferably according to theinvention.

In a thirteenth aspect, the invention provides a use of a blendaccording to the invention (cf. tenth aspect) in a process for producinga compression product, an elastic component or material, an elasticfibre, filament, thread, or yarn, or a compressive base fabric,preferably according to the invention.

In a fourteenth aspect, the invention provides a process for producing apolyurethane (PU) polymer containing N-diol comprising the steps of:

-   -   (i) Preparation of a quaternisable N-diol;    -   (ii) Preparation of a PU polymer containing a quaternisable        N-diol as produced in step (i);        -   and, optionally,    -   (iii) Quaternization of the PU polymer produced in step (ii).

In one embodiment of the process, the PU polymer is one according to theinvention.

In one embodiment, in step (ii) of the process, the quaternizable N-diolmonomer and a 1,4-butanediol is provided first, and apoly(tetrahydrofuran) is added subsequently. This embodiment ispreferred.

In one embodiment, in step (ii) of the process, the quaternizable N-diolmonomer and a poly(tetrahydrofuran) is provided first, and a1,4-butanediol is added subsequently.

In a fifteenth aspect, the invention provides a polyurethane (PU)polymer containing N-diol produced in accordance with a process of theinvention.

Finally, the invention considers individual features or combinationsthereof, as described above in respect of embodiments of a certainaspect, to be similarly realisable in embodiments under anotherdescribed aspect. Such embodiments are directly and unambiguouslyderivable from the whole content of the application, and the skilledperson will understand that such embodiments belong to the content ofthe application as filed.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides, amongst others, compression products comprisinga filament forming polyurethane (PU) polymer containing N-diol. This PUpolymer may be present in the form of a non-quaternised PU polymer(PU-N) or a quaternised PU polymer (PU-N+), also referred to as PUionomer, in which N-diol groups are quaternised. In either state, the PUpolymer shows a delayed continuous relaxation behaviour at roomtemperature.

Such compression products can be expanded easily by hand without muchphysical effort on the part of the user (FIGS. 1, 2 , phase (1)).Optionally, expansion can be supported or effected by the aid of anexpansion means, for example a handbag or pocket compatible expansionmeans. Once the external expansion forces cease (“release”), thecompression product starts relaxing and re-contracting in order toreturn to its original shape (FIG. 1 , phase (2)).

However, recovery of the original shape does not proceed linearly overtime, but is more and more delayed. While relaxation proceeds morelinearly at the beginning (FIG. 1 , phase (2)), the relaxation ratedecelerates during the subsequent, e.g., five, minutes (FIG. 1 , phase(3)), and decelerates even more during the next to minutes and above, upto hours (FIG. 1 , phase (3)).

Thus, a compression product comprising the N-diol containing PU polymerof the invention provides the user with good time to put on or apply theproduct in a widened shape to a part of the body, e.g. a leg in case ofa compression stocking (FIG. 2 ). There is no need to keep the productunder external expansion forces during application, as it is the casewith many conventional compression products. Then, the inventive productexerts a slowly increasing compression pressure on that part of the bodywhich it was applied to. This is more pleasant to the user than a suddenpressure built-up, and this is also favourable from a medicalperspective. For undressing or pulling off, the compression product isexpanded again, e.g. in case of a compression stocking step-wisetop-down, and is stripped off or removed.

In this way, a compression product of the invention is associated withincreased comfort when being applied, which, in turn, positively affectsthe compliance of the user.

Notably, relaxation of a stretched PU polymer according to the inventionis “self-initiated”, i.e. starts autonomously or spontaneously orintrinsically, i.e. without being triggered by any external stimulus oractivation source, as soon as the PU polymer is released. Accordingly,the compression products are applicable without the requirement ofadditional technical means or laborious and time-consuming operations.

In the end, use of the inventive compression products is not onlycomfortable and convenient, but also cost-effective.

The remarkable relaxation behaviour of the N-diol containing PU polymerof the invention, as compared to conventional elastic polymers, shall beillustrated with reference to FIG. 3 . When a sample of elastane isstretched, e.g. with a fixed rate from an original length of to mm to afinal length of 60 mm, and released (i.e. instant cease of stretchingforces), elastane immediately recovers its original length (FIG. 3A). Aconventional and commercially available PU polymer (i.e. not containingN-diol) recovers about 84% of its extended length immediately, butremains stretched by about 16% for a few days, i.e. does no recover itsoriginal length (FIG. 3B).

In contrast, as shown in FIG. 16 , the PU polymer of the invention,either non-quaternised or quaternised (with different degrees) shows arelaxation behaviour composed of an immediate relaxation phase (phase 2in FIG. 1 ) and relaxation phase of successive compression (phase 3 inFIG. 1 ).

In other words, compared to elastane and conventional PU polymers, thePU polymer of the invention shows a still continuous, but delayedrelaxation behaviour. Furthermore, as demonstrated by comparison withthe conventional PU polymer, this delayed relaxation behaviour dependson the presence of N-diol.

Moreover, the delayed relaxation behaviour can be controlled bymodifying the composition of the inventive PU polymer (in terms ofmonomer components, e.g. ratio of monomers), by quaternisation, and bythe degree of quaternisation. For example, a low degree ofquaternisation (e.g. 9% or 5%) of the inventive PU polymer led to afaster relaxation as compared to that of the correspondingnon-quaternised PU polymer, and to that of a PU-N+ polymer beingquaternised at 29%.

Finally, the relaxation behaviour of the PU polymer of the invention canbe further modified by admixture of elastane. The other way around,elastane can be provided with a delayed relaxation behaviour byadmixture of the inventive PU polymer. Such blends with elastane,depending on their relative compositions, open up new possibilities ofuses, for example in the field of in compression products.

Definitions

The terms “polyurethane (PU) polymer containing N-diol” or “N-diolcontaining polyurethane (PU) polymer”, as used herein, includes:

-   (1) A “non-quaternised polyurethane (PU) polymer”, i.e. a PU polymer    containing N-diol, the amino group of which are not quaternised, but    are tertiary amino groups. For simplification, “PU-N” is sometimes    used.-   (2) A “quaternised polyurethane (PU) polymer” or a “quaternised    polyurethane (PU) ionomer” or a “polyurethane (PU) ionomer”, i.e. a    PU polymer containing N-diol, the amino groups of which are at least    partially quaternised. For simplification, “PU-N+” is sometimes    used.

The term “quaternization”, as used herein, relates to a chemicalreaction in which a nitrogen atom (of a tertiary amino group) is gonefrom having three bindings to four bindings through alkylation,producing a 4-fold substituted derivative (i.e. a quaternary ammoniumcompound). The resulting compound may be referred to as being“quaternised”.

The “degree of quaternization”, as used herein, denotes the proportionof quaternary aminoalkyl groups relative to the total number ofaminoalkyl groups in a given compound.

An “ionomer” is defined as an ion-containing polymer with low mol % ofionic groups along the polymer backbone chains or as pendant groups. Theamounts of ionic groups distinguish an ionomer from a polyelectrolyte.Usually, ionomers are defined as containing an ion-content of up toaround 15 mol %.

Ionomers have been described in the prior art, e.g., ethylene/carboxylicacid ionomer fibres for gas filters (U.S. Pat. No. 5,882,519), orpolyurethane ionomers for films and laminates (U.S. Pat. No. 4,956,438).Further information can also be found in, e.g., Dieterich et al. (1970),Angew. Chem. internat. Edit. 9: 40-50; Kim et al. (1998), Polymer 39:2803-2808; Zhu et al. (2008), Polym. Adv. Technol. 19: 1745-1753.

The term “elasticity” (or “elastic”) defines the ability of a materialto resist a distorting influence or deforming force and to return to itsoriginal size and shape when that influence or force is removed. Forrubbers or other polymers, elasticity is caused by stretching of polymerchains when forces are applied.

The term “expansion”, as used herein, includes stretching, widening,extension, elongation, distortion, deformation, or other non-destructivechanges in shape of an elastic material. The term “expansion” is usedmore in relation to the deformation of a compression product or fabric,while the term “stretching” or “elongation” is used more in relation toan elastic polymer or fibre.

The term “compression product”, as used herein in some embodiments,refers to a product that, when worn by a patient, exerts a compressionon the wearer. Typically, it exerts such compression in those bodyregions of the patient that come into contact with the compressionproduct while it is being worn. Typically, also, a compression productis not a ridged product but is capable of being deformed, stretched,expanded, etc. whilst retaining a tendency or propensity to return toits original shape. The term “relaxation”, as used herein, refers to thebehaviour and condition of a previously expanded elastic material afterbeing released.

The term “release”, as used herein, refers to the cease of expansionforces or to the moment when such forces cease or stop.

The “first phase” of a relaxation process, as used herein, refers to an“expansion phase”, “stretching phase” or “active elongation phase”.During this phase, expansion or stretching forces are increasinglyapplied to the elastic material (or PU polymer or blend). In order tomaintain the amended shape or extended length, expansion or stretchingforces need to be applied further on.

The “second phase” refers to a phase of immediate relaxation or“immediate relaxation phase”. During this phase, the original shape orlength of the elastic material (or PU polymer or blend) is onlypartially recovered. Relaxation proceeds more linearly and thus thisphase may also be referred to as a “linear phase” or “stabile phase”.This second phase is self-initiated once the expansion or stretchingforces cease, i.e. in the absence of an external stimulus.

The “third phase” refers to a phase of successive relaxation or“successive relaxation phase”. During this phase, the elastic material(or PU polymer or blend) successively or gradually recovers its originalshape or length. Notably, the successive or gradual recovery is featuredby deceleration or increased retardation or growing delay or progressiveslow-down. In other words, the third phase may be subdivided in severalsub-phases during which relaxation proceeds with different velocities(for example at least a first sub-phase lasting, e.g., about 5 minutesand a second sub-phase lasting from, e.g., about 10 minutes up to 6hours). The third phase is also self-initiated and continues the secondphase. In particular in the context of a compression product, this phaseis also referred to as “successive compression phase”.

In the context of the third phase, the wording “recovers its originalshape”, “virtually recovers its original shape”, or “nearly completelyrecovers its original shape” means that the elastic material (or PUpolymer or blend) recovers by at least from about 85 to 100%, preferablyby from about 90 to 100%, more preferably by from about 95 to 100%, evenmore preferably by 100±5%, and most preferably by about 100% of theshape or total length to which the elastic material had been expandedduring the first phase. Alternatively, said wording means that theelastic material recovers to at least from about 100 to 150%, preferablyto from about too to 125%, more preferably to from about too to 110%,even more preferably to 100±5%, and most preferably to about 100% of itsoriginal shape or length, i.e. its shape or length prior to expansion.

The term “delayed relaxation behaviour” or “delayed continuousrelaxation behaviour”, as used herein, means that the relaxationbehaviour is delayed in time as compared to a reference relaxationbehaviour. Herein, the reference material may be any elastic polymer ora PU polymer not containing N-diol. The delay may relate to the durationof one or more phases of the relaxation process, or to the duration ofthe whole relaxation process.

The term “continuous” in connection with a “delayed continuousrelaxation behaviour” means that the relaxation process proceedscontinuously, either linearly or increasingly retarded, in any casewithout, e.g., temporary persistence of an intermediate shape.

The expression, as used herein, according to which “a monomer componentis derived from” or “is based on” a specific compound means that thecompound was used for preparing a polymer. Thus, the monomer componentcorresponds to the compound, but in a state in which the compound isbound within the polymer.

The term “about”, as used herein along with numbers or data, intends toinclude deviations (±) which usually are to be considered in therespective technical field.

Abbreviations

BD 1,4-butanediol

DBTL dibutyltin dilaurate

DMAE 2-dimethylaminoethylamine

DMTA dynamic-mechanical thermoanalysis

GPC gel permeation chromatography

HEA 2-hydroxyethylacrylate

MDI methylene diisocyanate, 4,4′-diphenylmethanediisocyanate

PU polyurethane

PU-N polyurethane containing N-diol, non-quaternised

PU-N+ polyurethane containing quaternised N-diol, quaternizedpolyurethane

P(THF) poly(tetrahydrofuran), poly(tetramethylenetherglycol) 1000

T_(g) glass transition temperature

TGA thermogravimetric analysis

THF tetrahydrofuran

Below, the invention will be illustrated further by means of thefollowing examples taking into account the accompanying figures, inwhich:

FIG. 1 shows diagrams (A) and (B) illustrating a phase of activeelongation (1), a phase of immediate relaxation (2), and a phase ofsuccessive compression (3), which a polyurethane (PU) polymer containingN-diol (PU-N or PU-N+) passes through in the course ofelongation—relaxation, and eventually recovery of original shape.

FIG. 2 shows phases (1) to (3) (see FIG. 1 ) in relation to anapplication procedure by a user (here: donning/doffing a compressionstocking).

FIG. 3 illustrates the relaxation behaviour of (A) elastane and (B) aconventional polyurethane polymer not containing N-diol (50% P(THF), 50%BD).

FIG. 4 shows a reaction scheme illustrating the chemical synthesis of aN-diol from 2-dimethylaminoethylamine (DMAE) and 2-hydroxyethylacrylate(HEA).

FIG. 5 shows a reaction scheme illustrating the chemical synthesis ofPU-N from N-diol, 1,4-butanediol (BD), poly(tetrahydrofuran) (P(THF)),and methylene diisocyanate (MDI).

FIG. 6 shows a reaction scheme illustrating the quaternisation of PU-Nusing 1-bromobutane, resulting in the production of PU-N+.

FIG. 7 shows the analysis by GPC (eluent: THF) of samples of PU-N+composed of different ratios of monomers.

FIG. 8 shows the analysis by TGA (25-800° C., 10 K/min, N₂) of samplesof PU-N+ composed of different ratios of monomers.

FIG. 9 shows the analysis by GPC (eluent: THF) of samples of PU-N+produced by different sequences of addition of monomers.

FIG. 10 shows the analysis by TGA (25-800° C., to K/min, N₂) of samplesof PU-N produced by different sequences of addition of monomers.

FIG. 11 illustrates the principle of quaternisation of the alkylaminogroup contained in PU-N+.

FIG. 12 shows the analysis by TGA (25-800° C., 10 o K/min, air) ofsamples of PU-N and PU-N+.

FIG. 13 shows analyses by DMTA of elastane (A), PU-N(B), (D), and PU-N+(C), (E). E′ [Pa]=dynamic modulus, tan δ=mechanic loss factor,T_(g)=glass transition temperature.

FIG. 14 shows results from stress-strain tests with elastane (A) orPU-N+ (B).

FIG. 15 shows results from stress-strain tests with elastane (A) orPU-N+ blended with 30% elastane (B).

FIG. 16 illustrates the relaxation behaviour of PU-N(A) and PU-N+ (B-D)having a quaternization degree of 29% (B), 9% (C), or 5% (D).

FIG. 17 shows a microscopic image (500× magnification) of α PU-N+ (i. e.quarternized polymer) spun into a filament that has been powdered with asuitable powder, e. g. SiO₂, to prevent sticking to the filament.

FIG. 18 shows results from stress-strain-tests with filaments of PU-N+.

FIG. 19 illustrates the relaxation behaviour of PU-N+ filaments

EXAMPLES

Briefly, Examples 1 and 2 relate to the preparation of N-diol containingPU polymer, Example 5 relates to the preparation of correspondingquaternised PU polymer. Generally, the preparation processes described,i.e. developed on a laboratory scale, are suitable for being processedto industrial-scale.

Examples 3 and 4 describe the characterisation of N-diol containing PUpolymers in regard to molecular mass and decomposition temperature;Example 6 describes the characterisation of quaternised PU polymers.

Examples 7 and 8 make comparisons of N-diol containing PU polymers andelastane in regard to glass transition temperature (T_(g)) and tensilestrength (modulus of elasticity, fracture strain).

Example 9 relates to blends of N-diol containing PU polymers andelastane, and describes their tensile strengths.

Examples 10 and 11 describe the relaxation behaviour ofN-diol-containing PU polymers and of blends with elastane, respectively.

In Table 16, characterising features of exemplary polymer samplesdescribed and discussed in some of the examples below, are summarized.

Example 1: Preparation of N-Diol

Chemicals

N,N-Dimethylethylendiamine (DMEA): CAS: 108-00-9, Acros, distilledbefore use; 2-hydroxyethylacrylate (HEA): CAS: 818-61-1, TCI, >95%; THF:technical grade, dried and distilled before use; Et₂O: technical grade,dried and distilled before use.

Chemical M [g · mol⁻¹] n [mol] M [g] D [g · cm⁻³] V [ml] eq. DMEA 88.150.594 48.42 0.807 60 1 HEA 116.12 1.099 127.57 1.106 115.3 2 THF 72.111.23 88.9 0.889 100 2.1Procedure

115.3 ml (1.099 mol) HEA and 100 ml THF were taken in a 500 ml3-neck-round-bottom flask under inert gas (argon) at room temperature(20±2° C.). 60 ml (0.594 mol) DMEA was added to this solution drop-wise.The mixture was stirred at 45° C. in an oil bath for 24 h. After thistime, the solvent was removed and the left over (yellowish liquid) wasextracted with Et₂O (4×100 ml Et₂O, product is not soluble in Et₂O). Theproduct was dried in vacuum at 50° C. Yield: 132 g, 75%.

The product was characterised by 1H-NMR spectroscopy.

A reaction scheme is shown in FIG. 4 .

Example 2: Preparation of Polyurethane (PU) Polymer Containing N-Diol(PU-N)

Chemicals

1,4-Butanediol (BD): CAS: 110-63-4, distilled before use; Poly(THF)1000: CAS: 25190-60-1, M_(n) (number average molar mass)=1,000 g/mol,Merck; 4,4′-diphenylmethanediisocyanate (MDI): CAS: 101-68-8, >97%, TCI;dibutyltin dilaurate (DBTL): CAS: 77-58-7, Sigma-Aldrich;

THF: technical grade, dried and distilled before use.

Reaction 1:

Chemicals M [g · mol¹] n [mol] M [g] D [g · cm⁻³] V [ml] eq. N-Diol (as320.19 0.00448 1.435 0.5 synthesized in Example 1) Poly(THF) 1,0000.00896 8.96 1 1000 BD 90.12 0.00448 0.404 1.02 0.396 0.5 MDI 250.250.01874 4.69 1.05 2.08 DBTL 631.56 1.22 · 10⁻⁴ 0.077 1.066 0.0726 0.5 wt% THF 72.11 0.247 17.78 0.889 20 27.5Reaction 2:

Chemicals M [g · mol⁻¹] n [mol] M [g] D [g · cm⁻³] V [ml] eq. Diol320.19 0.00896 2.87 1 (PH16N-6) Poly(THF) 1,000 0.00448 4.48 0.5 1000 BD90.12 0.00448 0.404 1.02 0.396 0.5 MDI 250.25 0.01874 4.69 1.05 2.08DBTL 631.56 0.985 · 10⁻⁴ 0.06 1.066 0.0563 0.5 wt% abs. THF 72.11 0.24717.78 0.889 20 27.5

Chemicals M [g · mol⁻¹] n [mol] M [g] D [g · cm⁻³] V [ml] eq. Diol320.19 0.00448 1.435 0.5 (PH16N-6) Poly(THF) 1000 0.00448 448 0.5 1000BD 90.12 0.00896 0.808 1.02 0.792 1 MDI 250.25 0.01874 4.69 1.05 2.08DBTL 631.56 0.903 · 10⁻⁴ 0.057 1.066 0.0535 0.5 wt% abs. THF 72.11 0.24717.78 0.889 20 27.5Procedure

MDI and DBTL were mixed with 20 ml dried THF in 100 ml nitrogen flaskunder argon. The solution was cooled in an ice bath. N-Diol und BD wereadded dropwise to this cooled solution within 10 min. After addition wasfinished, the mixture was stirred for 30 min at room temperature. Afterthis, poly(THF) was added dropwise and stirred for further 1 h.Afterwards, the reaction contents were heated at 50° C. (oil bathtemperature) for 2 h. Afterwards, the polymer formed was precipitated inMeOH and dried at 50° C. in vacuum. Yield: 89%.

A reaction scheme is shown in FIG. 5 .

Example 3: Comparison of Different Ratios of Monomers

PU-N synthesis as described in Example 2 was carried out based on ratiosof monomers given in Table 1 below.

TABLE 1 Sample N-Diol/eq. P(THF)/eq. BD/eq. MDI/eq. PH18N-6 1 0 0 1.04(Comp. sample) PH21N-6 1 0 1 2.08 (Comp. sample) PH15D-6 0 1 1 2.08(Comp. sample) PH23N-6 0.5 1 0.5 2.08 PH24N-6 1 0.5 0.5 2.08 PH18J-7 0.50.5 1 2.08 eq. = equivalent

Samples containing the PU-N product were analysed by GPC (FIG. 7 ) andTGA (FIG. 8 ).

Gel permeation chromatography (GPC) was used for molar massdetermination (instrument: Agilent Technologies 1200 Series/1260Infinity; column 1: PSS SDV 5 μm 100000; column 2: PSS SDV 5 μm 10000;column 3: PSS SDV 5 μm 1000; column 4: PSS SDV 5 μm 100; detector 1:Waters 486 UV; detector 2: Techlab Shodex RI; eluent: THF; flow rate:1.0 ml/min; column temperature: 40° C.; calibration standard:polystyrene).

Thermogravimetric analysis (TGA) was used to determine the thermalstability. A Netzsch TG 209 F1 Libra was used. Samples were heated from25 to 800° C. in Al₂O₃-pans. Ca. 5-10 mg polymers were measured with abalance and put in a sample-pan. Whole measurement was done under airwith a heating rate of 10° C./min. The temperature at which the weightloss started is mentioned as degradation temperature.

As shown in FIG. 7 , the molecular mass of PU contained in comparisonsamples PH18N-6 (100% N-diol) and PH21N-6 (50% N-diol, 50% BD) turnedout to be too low. The highest molecular mass was shown by comparisonsample PH15D-6 (50% P(THF), 50% BD).

Amongst PU-N samples PH24N-6 (50% N-diol, 25% P(THF), 25% BD), PH23N-6(25% N-diol, 50% P(THF), 25% BD), and PH18J-7 (25% N-diol, 25% P(THF),50% BD), the molecular mass increased with the amount of P(THF) and BD.

The results to be seen from FIG. 7 are summarised in Table 2 below.

TABLE 2 Sample Mn [g/mol] D PH18N-6 3.3 · 10³ 1.4 PH21N-6 5.7 · 10³ 1.9PH15D-6 7.5 · 10⁴ 1.8 PH23N-6 2.3 · 10³ 2.1 PH24N-6 1.6 · 10³ 2.2PH18J-7 3.1 · 10³ 2.0 Mn = molar mass; D = molecular mass [Da]

As shown in FIG. 8 , an increased amount of P(THF) or BD resulted in ahigher decomposition temperature.

The results to be seen from FIG. 8 are summarised in Table 3 below.

TABLE 3 Sample 5% decomposed [° C.] PH18N-6 199 PH21N-6 219 PH15D-6 307PH23N-6 278 PH24N-6 213 PH18J-7 246

Example 4: Comparison of Different Sequences of Addition of Monomers

PU-N synthesis as described in Example 2 was carried out by adding firstN-diol+P(THF) and subsequently BD (option 1), or by adding firstN-diol+BD and subsequently P(THF) (option 2).

Option 1: PH23N-6, PH24N-6, PH18J-7

-   -   (i) MDI+DBTL in abs. THF, cooling down on ice    -   (ii) Adding N-diol+P(THF) (in drops), stirring 30 min at room        temperature    -   (iii) Adding BD (in drops)        Option 2: PH12D-6, PH16J-7, PH17J-7    -   (i) MDI+DBTL in abs. THF, cooling down on ice    -   (ii) Adding N-diol+BD (in drops), stirring 30 min at room        temperature    -   (iii) Adding P(THF) (in drops)

The ratios of monomers were as given in Table 4 below.

TABLE 4 Sample N-Diol/eq. P(THF)/eq. BD/eq. MDI/eq. PH23N-6 0.5 1 0.52.08 PH12D-6 PH24N-6 1 0.5 0.5 2.08 PH16J-7 PH18J-7 0.5 0.5 1 2.08PH17J-7

Samples containing the PU-N product were analysed by GPC (FIG. 9 ) andTGA (FIG. 10 ).

As shown in FIG. 9 , addition of P(THF) after BD (option 2) resulted ina higher molar mass.

The results to be seen from FIG. 9 are summarised in Table 5 below.

TABLE 5 Sample Mn [g/mol] D PH23N-6 2.3 · 10⁴ 2.1 PH12D-6 4.3 · 10⁴ 2.1PH24N-6 1.6 · 10⁴ 2.2 PH16J-7 3.1 · 10⁴ 1.7 PH18J-7 3.1 · 10⁴ 2.0PH17J-7 4.0 · 10⁴ 1.6 Mn = molar mass; D = molecular mass [Da]

As to be seen from FIG. 10 , the sequence of addition of monomersvirtually showed no effect on the decomposition temperature.

The results to be seen from FIG. 10 are summarised in Table 6 below.

TABLE 6 Sample 5% Decomposition [° C.] PH23N-6 278 PH12D-6 271 PH24N-6213 PH16J-7 221 PH18J-7 246 PH17J-7 251

Example 5: Quaternisation of the N-Diol Containing PU Polymer

Chemicals

PU-N(as produced in Example 2); 1-bromobutane: CAS. 105-65-9,Merck, >98%; THF: technical grade, distilled before use.

Reaction

M [g · n D [g · Chemicals mol⁻¹] [mol] M [g] cm⁻³] V [ml] PU-N 101-Bromobutane 137.03 0.047 6.4 1.28 5 THF 72.11 0.889 30Procedure

10 g PU-N was dissolved in 30 ml THF at 60° C. 5 ml 1-bromobutane wasadded. The reaction mixture was stirred at 60° C. for different timeintervals to change the degree of quaternisation. The quaternisedpolymer was precipitated in hexane and dried at 50° C. in vacuum. Yield:96%.

The product PU-N+ was characterised by 1H-NMR spectroscopy.

A reaction scheme is shown in FIG. 6 , and FIG. 11 further illustratesthe principle of quaternisation.

The extent of quaternisation is exemplarily summarized in Table 7 below.

TABLE 7 Quaternisation Sample PU [%] PH06M-7_ PH16J-7_PU 29 PU-N+_24 h(50% N-diol, 25% P(THF), 25% BD) PH07M-7_ PH17J_PU 16 PU-N+_24 h (25%N-diol, 25% P(THF), 50% BD) PH07F-8_PU-N+ (50% N-diol, 25% P(THF), 25%BD 5

Example 6: Characterization of the Quaternised PU Polymer (PU-N+)

Samples containing non-quaternised or quaternised PU polymer (i.e. PU-Nor PU-N+) were analysed by TGA (FIG. 12 ). As shown, quaternisation didnot affect the decomposition temperature.

The results to be seen from FIG. 12 are summarised in Table 8 below.

TABLE 8 Sample 5% Decomposition [° C.] PH16J-7_PU 221 (50% N-diol, 25%P(THF), 25% BD) PH06M-7_PU-N+_24 h 224 (29% quarternized) PH17J-7_PU 251(25% N-diol, 25% P(THF), 50% BD) PH07M-7_PU-N+_24 h 246 (16%quaternised)

Example 7: Dynamic-Mechanical Thermoanalysis (DMTA)

Samples containing non-quaternised PU or quaternised PU polymer (i.e.PU-N or PU-N+) were analysed by DMTA; elastane served for comparison(FIG. 13 ).

For DMTA, a Rheometric Scientific DMTA instrument was used.

In contrast to elastane (FIG. 13A), the PU polymer samples showed glasstransition temperatures (T_(g)) of above 0° C., regardless of whetherthey were quaternised or not.

As furthermore shown, an increased amount of BD resulted in a higherglass transition temperature (FIG. 13B: T_(g)=40° C.; FIG. 13D:T_(g)=55° C.).

Finally, quaternisation of PU-N(resulting in PU-N+) induced an increasein the glass transition temperatures observed with the non-quaternisedPU-N(FIG. 13C: T_(g1)=70° C., i.e. >40° C.; FIG. 13E: T_(g1)=70° C.,i.e. >55° C.).

Example 8: Stress-Strain Test

Mechanical properties of the produced PU polymers were tested. For thatpurpose, samples of non-quaternised PU or quaternised PU polymer (i.e.PU-N or PU-N+) were analysed by a strain-stress test (tensile testing);elastane served for comparison.

For testing, a Zwick/Noell BT1-FR 0.5TN.D14 machine was used (pre-load:0.01 N/mm test rate: 50 mm/min). Sample preparation: 1 g PU (PU-N orPU-N+) was dissolved in to ml HFIP (hexafluoroisopropanol) and droppedon a glass plate for making a film. The film was dried at roomtemperature for 24 h followed by drying at 45° C. in vacuum for 24 h.The films were cut to the dimensions (W: 5 mm, L: ≥40 mm) for mechanicaltesting.

As shown in FIG. 14 , PU-N+ (FIG. 14B) showed a strain behaviourdifferent from that of elastane (FIG. 14A).

Furthermore, quaternisation induced a decrease in fracture strain, asshown in Table 9 below.

TABLE 9 E_(mod) Fracture strain Sample [MPa] dL [%] Ratio of monomersElastane 2.4 3,403 PH15D-6_PU 12.5 1,566 50% P(THF), 50% BD PH16J-7_PU37 1,388 50% N-Diol, 25% P(THF), 25% BD PH06M-7_ 154 796 50% N-Diol, 25%P(THF), PU-N⁺ 25% BD 29% quaternisation PH17J-7_PU 95 1,025 25% N-Diol,25% P(THF), 50% BD PH07M-7_ 98 780 25% N-Diol, 25% P(THF), PU-N⁺ 50% BD16% quaternisation E_(mod) = modulus of elasticity; dL = delta length; %= weight %; film thickness: 180 ± 20 μm

Example 9: PU Polymer/Elastane Blends

The produced PU polymers were blended with elastane (commerciallyavailable). Mechanical properties were tested using a strain-stress testas described in Example 8.

As shown in FIG. 15 , a blend of 70% PU-N+ and 30% elastane (FIG. 15B)showed a strain behaviour different from that of elastane (FIG. 15A).

Furthermore, fracture strain and modulus of elasticity measured withdifferent PU-N+/elastane blends are given in Table 10 below.

TABLE 10 E_(mod) Fracture strain Sample [MPa] dL [%] Ratio of monomersElastane 2.4 3,403 PH06M-7_PU-N⁺ 154 796 50% N-Diol, 25% P(THF), 25% BD29% quaternised PH07M-7_PU-N⁺ 98 780 25% N-Diol, 25% P(THF), 50% BD 29%quaternised Blend_10% 3.4 3,044 10% PH06M-7_PU-N⁺ + PH06M-7_PU-N⁺ 90%elastane Blend_30% 7.1 2,413 30% PH06M-7_PU-N⁺ + PH06M-7_PU-N⁺ 70%elastane Blend_50% 15 1,601 50% PH06M-7_PU-N⁺ + PH06M-7_PU-N⁺ 50elastane Blend_70% 31 1,097 70% PH06M-7_PU-N⁺ + PH06M-7_PU-N⁺ 30%elastane Blend_10% 3.4 3,060 10% PH07M-7_PU-N⁺ + PH07M-7_PU-N⁺ 90%elastane Blend_30% 6 2,331 30% PH07M-7_PU-N⁺ + PH07M-7_PU-N⁺ 70%elastane Blend 50% 14 1,710 50% PH07M-7_PU-N⁺ + PH07M-7_PU-N⁺ 50%elastane Blend 70% 39 1,301 70% PH07M-7_PU-N⁺ + PH07M-7_PU-N⁺ 30%elastane E_(mod) = modulus of elasticity; dL= delta length; % = weight%;film thickness: 160 ± 20 μm

For comparison, fracture strain and modulus of elasticity measured withdifferent PU-N(i.e. non-quaternised)/elastane blends are given in Table11 below.

TABLE 11 Fracture E_(mod) strain Sample [MPa] dL [%] Ratio of monomersPH02M-7_PU 50% N-Diol, 25% P(THF), 25% BD Blend_10% 3.7 3,262 10%PH02M-7_PU + PH02M-7_PU 90% elastane Blend_30% 5.2 2,900 30%PH02M-7_PU + PH02M-7_PU 70% elastane Blend_50% 5.5 2,325 50%PH02M-7_PU-N + PH02M-7_PU 50% elastane Blend_70% 6.8 2,492 70%PH02M-7_PU-N + PH02M-7_PU 30% elastane Blend_90% 8.8 1,544 90%PH02M-7_PU-N + PH02M-7_PU 10% elastane E_(mod) = modulus of elasticity;delta length; % = weight %; film thickness: 140 ± 10 μm

Example 10: Relaxation Behaviour

A sample of non-quaternised PU (PU-N) or of corresponding quaternised PU(PU-N+), 29% quaternisation, was stretched from 10 mm (original samplelength) to 40 mm (FIGS. 16A, 16B). Upon release, both samples recoveredtheir original sample lengths in about 6 hours. In doing so,approximately 180% recovery was achieved in about 5 min, after which theremaining 120% was recovered much more slowly. In this respect, therelaxation behaviour of PU-N and PU-N+ was almost the same.

Similarly, samples of PU-N+ having different degrees of quaternisation,namely 9% or 5%, were stretched from 10 mm to 50 mm (FIGS. 16C, 16D).Upon release, 300% and 280% of the original sample length was recoveredimmediately, and further 140% and 160% was recovered after 5 min,respectively. Thus, approximately 90% total recovery was achieved withinabout 5 min.

Thus, the relaxation behaviour depends, at least partially, on thedegree of quaternisation.

The results to be seen from FIG. 16 are summarized in Table 12 below.

TABLE 12 Immediate Relaxation 1 Relaxation 2 Ratio of Sample relax. [%][%/time] [%/time] monomers PH16J-7_PU 100 80/5 min 120/6 h 50% N-diol,25% P(THF), 25% BD PH06M-7_PU- 80 100/5 min 120/6 h 50% N-diol, 25% N+P(THF), 25% BD (derived from 29% PH16J-7_PU quaternisation PH23M-7_PU-300 140/5 min 60/60 min 50% N-diol, 25% N+ P(THF), 25% BD (derived from9% PH02M-7_PU) quaternisation PH30M-7_PU- 280 160/5 min 60/6o mm 50%N-diol, 25% N+ P(THF), 25% BD (derived from 5% PH02M-7_PU)quaternisation

Example 11: Relaxation Behaviour of PU Polymer/Elastane Blends

Non-quaternised PU (PU-N) or corresponding quaternised PU (PU-N+) havingdifferent degrees of quaternisation (29%, 9% or 5%) were blended withelastane (commercially available), respectively. Samples were subjectedto stretching-and-release similar to the description in Example 10(stretching of samples from 10 to 50 mm).

The results are summarized in Tables 13 to 15 below.

TABLE 13 Blends of PU-N (PH02M-7_PU; 50% N-diol, 25% P(THF), 25% BD) andelastane. Immediate PU-N Elastane relaxation Relaxation 1 Relaxation 2[wt %] [wt %] [%] [%/time] [%/time] 10 90 450 30/5 min 20/10-20 min 3070 430 40/5 min 30/10-20 min 50 50 420 50/5 min 30/2 h 70 30 410 60/5min 30/3 h 90 10 390 80/5 min 30/6 h

Firstly, admixture of elastane to PU-N altered the relaxation behaviourof the individual PU-N and of elastane.

As to be seen from Table 13, the blends showed approximately 80 to 90%total recovery immediately after release, depending on the relativeamounts of PU-N and elastane. Recovery of the remaining 10 to 20% tookabout 15 min to 6 hours, also depending on the relative amounts of PU-Nand elastane. More generally, increased relative amounts of PU-Nresulted in an increase in total relaxation time.

TABLE 14 Blends of PU-N+, 29% quaternisation (PH06M-7_PU-N+; 50% N-diol,25% P(THF), 25% BD) and elastane. Immediate PU-N+ Elastane relaxationRelaxation 1 Relaxation 2 [wt %] [wt %] [%] [%/time] [%/time] 10 90 44020/5 min 40/30-60 min 30 70 400 40/5 min 60/2 h 50 50 340 100/5 mm 60/3h 70 30 280 120/5 min 100/6 h

As to be seen from Table 14, increased relative amounts of PU-N+resulted in an increase of total relaxation time. Furthermore, comparedto non-quaternised PU-N (Table 13), PU-N+ was associated with increasedtotal relaxation times. Apart from that, PU-N+ with a high degree ofquaternisation (29%) does not provide any particular advantage overnon-quaternised PU-N when used in blends with elastane.

TABLE 15 Blends of PU-N+, 9% quaternisation (PH23M-7_PU-N+; 50% N-diol,25% P(THF), 25% BD) and elastane. Immediate PU-N+ Elastane relaxationRelaxation 1 Relaxation 2 [wt %] [wt %] [%] [%/time] [%/time] 50 50 39080/5 min 30/30-60 min 60 40 350 100/5 min 50/30-60 min 70 30 380 90/5min 30/30-60 min

As to be seen from Table 15, blends with PU-N+ having a lower degree ofquaternisation (here: 9%) showed relaxation times of about 30 min to 1 hfor all tested compositions. Apart from that, the relaxation behaviouris very similar to that of blends with non-quaternised PU-N, i.e.approximately 80% total recovery was achieved immediately.

TABLE 16 Blends of PU-N+, 5% quaternisation (PH30M-7_PU-N+; 50% N-diol,25% P(THF), 25% BD) and elastane. Immediate PU-N+ Elastane relaxationRelaxation 1 Relaxation 2 [wt %] [wt %] [%] [%/time] [%/time] 50 50 39070/5 min 40/30-60 min 60 40 380 80/5 min 40/30-60 min 70 30 380 80/5 min40/30-6o min

As to be seen from Table 16, the relaxation behaviour of blends withPU-N+ having a low degree of quaternisation (here: 5%) is very similarto that of blends with PU-N+, 9% quaternisation (Table 15), and ofnon-quaternised PU-N (Table 13).

TABLE 17 Number T_(g) or T_(g1)/T_(g2), Degradation dL [%] N- Degree ofaverage [° C.] temperature (pre-load: 0.01 Diol:P(THF):BD quaternisationmolar mass (from [° C.] E_(mod) N/mm; speed: Sample (molar ratio) [%] Mn[g/mol] DMTA) (from TGA) [MPa] σ_(M) [MPa] 50 mm/min) Elastan 0 7.54 ·10⁴ −50 243 2.4 27 3,403 PH15D−6_PU 0:1:1 0 3.06 · 10⁴ −25 230 12.5 331,566 PH16J−7_PU 1:0.5:0.5 0 40 185 37 35 1,388 PH06M−7_PU-N + 1:0.5:0.524 h/29% 40/70 182 154 42 796 (derived from PH16J−7_PU) PH23M−7_PU-N +1:0.5:0.5 90 min/9% 29 12 968 (derived from PH02M−7_PU) PH30M−7_PU-N +1:0.5:0.5 45 min/5% 12 11 1,056 (derived from PH02M−7_PU) Blend_30% 4 193,082 PH16J−7_PU + 70% elastane Blend_50% 4.9 19 2,629 PH16J−7_PU + 50%elastane Blend_70% 5.9 16 2,412 PH16J−7_PU + 30% elastane Blend_10% 3.728 3,262 PH02M−7_PU + 90% elastane Blend_30% 5.2 28 2,900 PH02M−7_PU +70% elastane Blend_50% 5.5 20 2,325 PH02M−7_PU + 50% elastane Blend_70%6.8 21 2,492 PH02M−7_PU + 30% elastane Blend_90% 8.8 16 1,544PH02M−7_PU + 10% elastane Blend_50% 6.3 15 1,896 PH23M−7_PU-N + 50%elastane Blend_60% 9.9 18 2,067 PH23M−7_PU-N + 40% elastane Blend_70%10.5 15 1,990 PH23M−7_PU-N + 30% elastane Blend_50% 6.2 14 1,800PH30M−7_PU-N + 50% elastane Blend_60% 7.2 16 2,187 PH30M−7_PU-N + 40%elastane Blend_70% 8.8 13 1,951 PH30M−7_PU-N + 30% elastane

Example 12: Polymer Fibres/Filaments

A sample of quaternised PU polymer (PU-N+) (PH07F-8_PU-N+=50% N-Diol,25% P(THF)25% BD, 5% quaternised (5% N+)) was milled to a powder usingan ultra-centrifugal mill ZM200. The milling machine had a sieve withpore diameter of 1 mm. Machine with any other pore diameter can also beused and sieve diameter is not important. Idea was to convert a mass ofthe polymer into a powder that can be easily fed to extruder for makingfilaments. Thereafter it was spun as a mono-filament using a twin screwextruder (process 11 from Thermo Scientific). The extruding filamentswere continuingly passed through a trough having SiO2 powder to preventany residual stickiness/tackiness of the filament and allowed storage ofthe filament, when it has been wound up into a roll without sticking toeach other). Using this set up, the melt spinning of the PU ionomer intoa mono-filament is easy, and a large scale production is possible.

An exemplary microscopical image of such filament is shown in FIG. 17(500× magnification). The filaments are not transparent and have anopaque surface.

Mechanical properties of the spun filament were tested. For thatpurpose, the produced filament(s) were analyzed by a strain-stress test(tensile testing). For testing, a Zwick/Noell BT1FR0.5TN.D14 machine wasas used. (Preload: 0.1 kPa, test rate: 50 mm/min). The filament had adiameter of 280+/−30 Gm, and the filament was subjected to tensiletesting

The following results were achieved:

Fracture E_(mod)/ strain dL F (max)/ Sample MPa [%] MPa Monomer ratioPH07F-8_PU- 2,5 1100 29 50% N-Diol, 25% P(THF), N⁺_filament_with 25% BD,5% N⁺ SiO₂_powderE _(mod)=modulus of elasticity; d _(L)=delta length; %=weight percent;filament diameter=208+−30 μm

The results of the strain-stress test are shown in FIG. 18 .

The relaxation behavior of such filaments are shown in FIG. 19 . Forsuch relaxation behavior, a filament of quaternised polyurethane polymerwas stretched from 10 mm (original filament length) to 50 mm. Uponrelease, the filament recovered its original sample length inapproximately 35-65 min.

In summary, in this example, the inventors have shown thatpolyurethane-ionomer can be reproducibly spun into filaments thetackiness of which can be prevented by dusting with SiO₂-powder or asimilar powder or a suitable oil. The powder does not interfere with therelaxation behavior.

The invention claimed is:
 1. A compression product comprising an elasticcomponent or material, the elastic component or material having adelayed continuous relaxation behavior, the elastic material beingcapable of applying a compression or a supporting force or a localpressure to a part of the body of a subject, the elastic materialfurthermore being capable of passing through a first phase during whichthe material is expanded, a second phase during which the component ormaterial relaxes without recovering its original shape, and a thirdphase during which the component or material recovers its original shapewith successive deceleration, wherein relaxation is self-initiated inthe absence of an external stimulus, wherein the relaxation behavior isdelayed in time as compared to an elastic component or material notcontaining N-diol, wherein the elastic component or material comprises:(a) a non-quaternized polyurethane (PU) polymer containing N-diol(PU-N); and/or (b) a quaternized polyurethane (PU) polymer or ionomercontaining quaternized N-diol (PU-N+); and, optionally, (c) elastane. 2.The compression product according to claim 1, which is selected from thegroup consisting of a compression hosiery, a compression stocking, sock,knee sock, tights, panty hose, maternity panty hose, a compression kneeguard, a compression arm sleeve, a compression waist attachment, belt orgirdle, a compression bandage, a body-supporting bandage, an orthosis, aprosthesis liner, a compression wound dressing, a compression plaster orpatch, and a compression garment.
 3. The compression product accordingto claim 1, comprising an elastic component or material comprising anon-quaternized PU polymer and, optionally, elastane.
 4. A method ofproviding compression to a subject in need of such compression, whereinsaid method comprises applying to a body part of the subject acompression product according to claim 1 in a field of phlebology,orthopaedics, foot care, surgery, post-surgery care, trauma management,wound care, or sports; or for treatment or prevention or management ofimpaired musco-venous pump performance, compromised venous circulation,venous insufficiency, oedema, phlebitis, thrombosis, venous embolism,lymphoedema, ulcer, aching legs, varicose veins, spider veins, or the“economy class syndrome” (ECS).
 5. A polyurethane (PU) polymer having adelayed continuous relaxation behavior, wherein relaxation is initiatedautonomously or spontaneously in the absence of an external stimulus,wherein the PU polymer contains at least one N-diol monomer component,and wherein the relaxation behavior is delayed in time as compared to aPU polymer not containing N-diol.
 6. The polyurethane (PU) polymeraccording to claim 5, which is a non-quaternized PU polymer (PU-N). 7.The polyurethane (PU) polymer according to claim 5, which is aquaternized PU polymer (PU-N+) or a quaternized PU ionomer (PU-N+). 8.The polyurethane (PU) polymer according to claim 5, wherein the N-diolmonomer component is derived frombis(2-hydroxyethyl)-3,3′-((2-(dimethylamino)ethyl)azanediyl)-dipropionateorN′,N′-bis(3-(2-hydroxyethoxy)-3-oxopropyl)-N,N-dimethylethylendiamine.9. The polyurethane (PU) polymer according to claim 5, comprising afirst molecular unit consisting of a N-diol monomer component and anisocyanate monomer component, a second molecular unit consisting of a1,4-butanediol monomer component and an isocyanate monomer component,and a third molecular unit consisting of a P(THF) monomer component andan isocyanate component.
 10. The polyurethane (PU) polymer according toclaim 9, the relative amounts of N-diol, P(THF) and 1,4-butanediolmonomer components being about 50:25:25%.
 11. The polyurethane (PU)polymer according to claim 7, wherein the quaternized PU polymer orionomer comprises an amount of quaternized N-containing groups of up toabout 15% of ionic groups, related to the total moles of the PU polymer.12. The polyurethane (PU) polymer according to claim 5, having a glasstransition temperature T_(g) of between about 20 and 60° C.
 13. A blendcomprising: (a) a non-quaternized polyurethane (PU) polymer containingN-diol (PU-N) having a delayed continuous relaxation behavior, whereinthe relaxation behavior is delayed in time as compared to a PU polymernot containing N-diol; and/or (b) a quaternized polyurethane (PU)polymer or ionomer containing quaternized N-diol (PU-N+) having adelayed continuous relaxation behavior, wherein the relaxation behavioris delayed in time as compared to a PU polymer not containing N-diol;and (c) elastane.
 14. The blend according to claim 13, comprisingbetween about 5 and 40% (by weight) non-quaternized PU polymer, andbetween about 60 and 95% (by weight) elastane.
 15. A method forproducing a compression product; an elastic component or material; anelastic fibre, filament, thread, or yarn; or a compressive base fabric;wherein said method comprises the use of a polyurethane (PU) polymerhaving a delayed continuous relaxation behavior, wherein relaxation isinitiated autonomously or spontaneously in the absence of an externalstimulus or the use of a blend according to claim
 13. 16. A process forproducing a polyurethane (PU) polymer containing N-diol, the PU polymercontaining at least one N-diol monomer component, the PU polymer havinga delayed continuous relaxation behavior, wherein the relaxationbehavior is delayed in time as compared to a PU polymer not containingN-diol, the process comprising the steps of: (i) Preparation of aquaternizable N-diol; (ii) Preparation of a PU polymer containing thequaternizable N-diol as produced in step (i); and, optionally, (iii)Quaternization of the PU polymer produced in step (ii).
 17. The processaccording to claim 16, wherein the N-diol monomer component is derivedfrombis(2-hydroxyethyl)-3,3′-((2-(dimethylamino)ethyl)azanediyl)-dipropionateorN′,N′-bis(3-(2-hydroxyethoxy)-3-oxopropyl)-N,N-dimethylethylendiamine.18. A polyurethane (PU) polymer containing N-diol produced in accordancewith the process according to claim 16, wherein the PU polymer has adelayed continuous relaxation behavior, wherein the relaxation behavioris delayed in time as compared to a PU polymer not containing N-diol.